.Biden preparing to block out Nippon Steel investment of united state Steel The Washington PostU.S. Steel says it could leave behind Pittsburgh if Nippon bargain falls through as Biden prepares to block out requisition Pittsburgh Post-GazetteBiden Expected to Block U.S. Steel Requisition The New York TimesExclusive|United State Steel Portend Vegetation Closings if Sale Collapses The Commercial JournalBiden prepared to shut out US Steel investment through Nippon Steel CNN.